A mobile system is provided with a function of call waiting, i.e., when the terminal receives a second call during a conversation, the terminal prompts the user that there is another incoming call. The prompting manner includes voice prompt and screen text prompt. In this case, the user only needs to press the answer key if he needs to connect the second call, and meanwhile, he can hold the first call connected. The user can switch to the first call if he presses the answer key again, and meanwhile keeps the second call connected, thereby achieving conversation switch between two calls by pressing the answer key.
A cluster system is provided with a function of incoming call prompt on busy. Similar to the call waiting function in the mobile system, when a terminal receives another cluster call when in a cluster conversation, the terminal prompts the user that there is another cluster incoming call. The prompting manner is voice prompt, and meanwhile related information such as the terminals of another cluster call and the cluster group number is displayed by way of screen text.
However, when a mobile system enters a cluster system, i.e., when the terminal has a mobile incoming call when in a cluster conversation; or when the terminal has a cluster incoming call when in a mobile conversation, the base station cannot know the status of the called terminals, and thus cannot send call waiting prompt information to the called terminals.